We have integrated Google Maps into the customer sections on ProMart 2.0. You can view your customers on a map individually or you can search for all your customers in a specific postcode, you can also see how much they have spent in the last 24 months. This is great when you are going to see a client as you can see which of your other customers are near your destination.
When we setup your site and import your customers we geocode all the postcodes on mass and store the LAT and LONG in the database so we can place map markers without new calls to the google maps API. This allows us to plot thousands of markers on the map at any time without exceeding the Google Maps API limit.